Improvement in rotary pumps



l Nirsn STATES MONROE STANNARD, OF NEW BRITAIN, ASSIGNOR TO PRATT, WHITNEY & CO., OF HARTFORD, CONNECTICUT.

IMPROVEMENT IN ROTARY PUMPS.

' Specification forming part of Letters Patent No. 33,126, dated August 20, 1561.

i .To all whom it may concern:

Be it known that I, MONROE STANNARD, of New Britain, in the county of Hartford and State of Connecticut,have invented certain new and useful Improvements in Fluid Motors, Meters, and Pumps; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 represents a side elevation of the interior of a Water meter or motor with my improvement applied, the end of the case c and the end plate of the drum a being removed. Fig. 2 is a vertical cross-section through the case c. Fig. 3 is a longitudinal section of the apparatus at line x y, Fig. 2; and Fig. 4 illustrates the application of my invention to a meter or motor having three movable abutments.

Similar letters of reference denote the same parts in all the figures.

My invention relates to that kind of apparatus for measuring, pumping, or obtaining power from fiuids,in which the liuids acts upon or (in the case of pumps) is acted upon by sliding abutments or valves, which are successively protruded from a rotating drum into asurroundingchannel,through which the iiuid moves, having for its object to render the apparatus more nearly frictionless; and to this end my said invention consists in providing passages for the admission of the fluid to the abutment-chambers behind-the end of the abutments, substantially in the manner and for the purposes hereinafter set forth; and my said invention alsocons'ists in limiting the extent to which the movable abutments may be protruded by means of gage-screws, substantially in the manner and for the purpose specified.

To enable others skilled in the art to make and use my invention, I will proceed to a description thereof.

In the accompanying drawings, a is a cylindrical drum, which is free to revolve on its axis b within a concentric cylindrical case, c, of sufficient diameter to allow a proper channel-way, d, around the drum c. This channelway is interrupted by an abutment, e, xed to the case and forming a water-tight fit against the surface of the drum a. The inlet-opening f is located on one side of the abutment e and the outlet g is on its opposite side.

h h are pistons, which slide in chambers t' i, formed in the drum c, and are moved in and out by rollers k, which run in cam-grooves Z, formed in the ends of the case c. These camgrooves are of such form and the relative positions of the inlet, the outlet, and the abutments are such that one or another of the abutments 7L is always so thrust out as to out off direct communication between the inlet and outlet openings. The fluid cannot, therefore, pass through the apparatus, except as the rotation of the drum c in the direction of the arrows allows it, or, in the case of a pump, forces it. The abutments are drawn into the drum after they have reached the outlet, in order that they may pass by the lxed abutment e.

It has been found in practice that when the pistons h are tted to slide water-tight on all sides in the chambers z' the resistance to moving them out against the hydrostatic pressure on their outer ends is so great that the apparatus is uncertain in its operation when used to measure fluids under slight pressure, and that when used as a motor or as a pump a large percentage of its power is lost. iI have overcome this difficulty by providing passages m in the drum a, leading from the channel d, in which the fluid moves to the lower part of the chambers i, so that there shall always be the same pressure behind the end of the abutment as there is in that part of the channel (l into which the passage m opens, and I prefer to make these passages open into the channel d on the working side of the abutments--that is to say, on the side on which the greatest hydraulic pressure is exerted-because thereby the abiitments, when in close contact with the inner surface of the case c, are kept forced ont by the pressure on their rear or inner ends, and this obviates the necessity of forming the cam-grooves Z with thataccuracy which would be required if they were depended on to keep out the abutments.

The passages m, instead of being made in the drum, may be formed in the abutments h.

In order that the pistons h may not be forced larged heads of these screws form checks to prevent the abutments being forced out only just so far as to prevent leakage of iiuid past their ends. It has been found that in practice the friction may thus be greatly reduced Without occasioning sensible leakage, and alf though. I prefer to use the gage-screws, arranged as described, yet other kinds of adjustable gages may be employed to regulate the point to which the abutments can be protruded, all Within the scope of my invention.

Diselaiming the general form and mode of operation of the motor, meter, or pump herein described,

What I claim as my invention, and desire to secure by Letters Patent, is

l. The employment of the passages m, leady ing into the abutment-chambers, substantially I as and for the purpose hereinbefore specified. 2. The employment of adjustable gages to limit the distance to which the pistons may be protruded, substantially in the manner and for the purpose hereinbefore set forth.

MONROE STANNARD/ Witnesses:

CRAs. C. SHULTAs, GEO. S. GILMAN. 

